Bacterial source

Clinical manifestation of vitamin B 2 deficiency is usually a result of absence of the gastric absorptive (intrinsic) factor. Dietary deficiency of vitamin B 2 is uncommon and may take 20 to 30 years to develop, even in healthy adults who foUow a strict vegetarian regimen. An effective enterohepatic recycling of the vitamin plus small amounts from bacterial sources and other contaminants greatly minimizes the risk of a complete dietary deficiency. Individuals who have a defect in vitamin B 2 absorption, however, may develop a deficiency within three to seven years. 

Since many therapeutic enzymes are still derived from bacterial sources, FDA requirements can serve to make the commercial preparations more expensive. However, toxicological examination of each lot may not be necessary when the purification procedures yield reproducible preparations. 

Porin and Bacterial Source Pore Diameter (nm) Mj. Exclusion Limit... 

C2H5OH, ethanol is formed by bacteria in the gastrointestinal tract in low amounts. Most of the ethanol of bacterial source is metabolized during the first liver passage yielding acetaldehyde and subsequently acetic acid. 

The KDO aldolase (KdoA, EC 4.1.2.23) is involved in the catabolism of the eight-carbon sugar d-KDO, which is reversibly degraded to D-arabinose (15) and pyruvate (Figure 10.10). The enzyme has been partially purified from bacterial sources and studied for synthetic applications [71,74]. It seems that the KdoA, similar to... 

Endonuclease Sequence Recognized Cleavage Sites Shown Bacterial Source... 

Tetrodotoxin (TTX) and saxitoxin (STX) are potent sodium channel blockers that are found in phylogenetically diverse species of marine life. The wide distribution of TTX and STX has resulted in speculation that bacteria are the source of these toxins. Recently, investigators have reported isolation of marine bacteria, including Vibrio Alteromonas, Plesiomonas, and Pseudomonas species, that produce TTX and STX. This chapter details the methods and results of research to define bacterial sources of TTX and STX. 

This chapter reviews recent experimental evidence of a bacterial source of sodium channel blockers, principly TTXs. These findings support the hypothesis that procaryotic organisms produce TTXs which contaminate oceanic food chains. 

J. E. Loper and M. N. Schroth, Influence of bacterial sources of indole-3-acetic acid on root elongation of sugar beet. Phytopathology 76 386 (1986). 

Recently, a new natural product linking sulfur, oxygen and iron has been isolated from bacterial sources. These substances, the thiohydroxa-mic adds, are worthy of discussion in the present context even though their biological significance has yet to be defined. The copper and iron complexes of N-methyl thioformylhydroxamic acid were obtained from the culture broth of Pseudomonas fluorescens and named fluopsins C and... 

Owing to their pivotal role in mammalian signal transduction, there has been an intense interest in the enzymes of the PLC superfamily. Progress toward understanding the mechanism, structure, and function of PI-PLCs from both bacterial and mammalian sources has been particularly impressive [12-15]. Several PI-PLCs have been isolated and cloned, and a number of high resolution, three-dimensional X-ray structures are available [16-19]. In contrast to the advances that have been made with mammalian PI-PLC isoenzymes, their PC-PLC counterparts are poorly characterized. Studies with mammalian PC-PLCs have typically been conducted with partially purified enzymes, and there has not been a report of the isolation of a pure, eukaryotic PC-PLC. To circumvent the currently intractable problems associated with mammalian PC-PLCs, PLCs from bacterial sources have been sought as potentially useful models. 

The structural components encountered in E. coli are also present in lipid A of other bacterial sources. Thus, a survey of the structures analyzed shows that lipid A, in general, contain two g/wcoconfigured and pyranosidic D-hexosamine residues (2-amino-2-deoxy-D-glucose, GlcpN, or 2,3-diamino-2,3-dideoxy-D-glucose, GlcpN3N, also termed DAG (49,50)], which are present as a ) -(l — 6)-linked disaccharide (monosaccharide backbones have also been identified, but the respective lipid A lack endotoxic activity). The disaccharide is phosphorylated by one or, in most cases, two phosphate... 

Luciferase from bacterial sources catalyses the oxidation of long chain aliphatic aldehydes and requires the coenzyme FMN. The wavelength of the emitted radiation in this reaction is approximately 490 nm ... 

Some enzymes with improved single amino acid specificity are commercially available. An example is phenylalanine dehydrogenase (EC 1.4.1.1), derived from bacterial sources, which acts on phenylalanine with the simultaneous conversion of NAD to NADH. Quantitation of the phenylalanine is based on determining the amount of NADH produced using standard procedures. In the direct methods, the absorbance at 340 nm is measured, whereas in the colorimetric methods, the reaction is coupled to an electron acceptor... 

Figure 7.18 A comparison of the Ni K-edge X-ray absorption spectra for redox-poised samples of hydrogenases from different bacteria in the edge and XANES regions.Spectra are separated by redox level, with line types indicating the different bacterial sources (bold line, t roseopersicina light line, D. gigas dotted line, A vinosum dashed line, D. desulfuricans ATCC27774 dashed-dot line, coli). Reprinted with permission from Gu, et a/. (1996) and the American Chemical Society.

Although streptomycin was not the first antibiotic (penicillin, a fungal product, had been isolated some years earlier), its discovery was a landmark in antibiotic history. It was the first effective therapeutic for tuberculosis, a disease that had terrorized humans for cenmries and a cause of human morbidity and mortality unmatched by wars or any other pestilence. Streptomycin was the first aminoglycoside to be identified and characterized and is noteworthy in being the first useful antibiotic isolated from a bacterial source. At the present time, the use... 

This zinc-dependent enzyme [EC 3.1.4.3] (also known as lipophosphodiesterase I, lecithinase C, Clostridium welchii ce-toxin, and Clostridium oedematiens 13- and y-toxins) catalyzes the hydrolysis of a phosphatidylcholine to produce 1,2-diacylglycerol and choline phosphate. The enzyme isolated from bacterial sources also acts on sphingomyelin and phosphatidylinositol however, the enzyme isolated from seminal plasma does not act on phosphatidylinositol. See Micelle... 

One of the earliest recognized Fe S proteins was that associated with mitochondrial electron transport (Rieske et al., 1964). Even in the first partial in vivo characterization it was apparent that the protein had spectral properties that set it apart from the bacterial and plant-type ferredoxins which had just been discovered. Namely, the EPR spectrum had a gave near 1.91 and the high-held g value was shifted upheld. Furthermore, the protein had an Eq of approximately -t-250 mV, 600 mV more positive than the ferredoxins. Due to the instability of the protein, a more detailed analysis was not possible until the 1980s, when an analogous protein was isolated from bacterial sources (Fee etal., 1984). The ensuing... 

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